This invention relates generally to a process and an apparatus for the biological conversion (composting) of organic materials in biomass wherein the organic materials are treated by finely comminuting and mixing them for a time in a substantially enclosed environment.
It is known to one skilled in the art that organic materials, in particular wastes from private households, restaurants etc., may be converted (composted) into reusable, valuable biomass (compost or decomposed material). It is known from German patent specification DE-C-38 37 865 to compost in a drum-shaped reaction container used together with a separate conditioning apparatus wherein material, prior to being put into the reaction container, is ground, or comminuted, to a suitable particle size, thereby allowing composting in the reaction container with a shortened starter phase (that is, the composting is accelerated more quickly). The advantage of having a fast acting conversion reaction must be weighed against relatively cost-intensive apparatus therefor, usually not suitable for stationary use in restaurant operations and the like. It is further known from prior art to compost in a one-step procedure with relatively compact apparatus (German patent specification DE-C-38 44 700) wherein the grinding and mixing of the material to be treated takes place in one and the same reactor until thorough composting is achieved. In this regard, it is also known (compare for example German patent DE-A-38 19 979) to accomplish one-step composting in a pivotal drum. The pivotal drum may, for example, be separated into two chambers (U.S. Pat. No. 38 37 810; German patent application DE-A-40 00 916) thereby allowing alternating operation so that smaller batches may be processed. One-step batch composting entails a comparatively long treatment period due to a necessarily long starter period for each batch even when, as already suggested (British patent document GB-C-1 022 127), the material to be treated is provided with a suitable quantity of microorganisms for speeding up the conversion process. Thus, a product is often thereby produced which is unsuitable for immediate use, for example in nurseries and the like, without further treatment. On the other hand, apparatus of the latter kind have the advantage, due to their compactness, that they are basically suitable for an economical, stationary use at a place of waste creation.
It is an object of this invention to provide a process and an apparatus as described above suitable to allow a conversion of wastes into a reusable biomass in a shortened treatment time period at a place of waste generation in a quasi-continuous process. This invention is geared in particular to an improvement of the biological conversion procedure of the invention of German patent De-C-38 44 700.